south Italian politics and contributed to the constant confiscation and invasion of monastic estates as lay barons sought to increase their power against their foes during the war-filled eleventh and twelfth centuries. The arrival of the Normans, adept castle-builders, in the early eleventh century only exacerbated the tendency toward fortification of every hilltop. Together with the Prince of Salerno, they subdued Calabria and encastellated its mountainous territory, leading to the inevitable invasion of Sicily. Spain The encastellation of Spain is inextricably linked to the Reconquista. That said, encastellation occurred mostly in the centre of the peninsula. This region, originally a county of the Kingdom of León, even adopted the name Castile because of its many castles. The castles first began to spread quickly in the tenth century, in light of the increasing power of the Castilian counts vis-à-vis the king. During the long reign of Count Fernán González, Castile became de facto independent and its castles multiplied. Britain True medieval castles were a somewhat later arrival in Britain than in continental Europe. The process of encastellation in Britain is as inextricably linked to Normanisation (which is, of course, linked to the Norman Conquest) as the encastellation of Spain is to the Reconquista. England Normanisation began in England before the Conquest primarily through the Norman sojourn of Ethelred II and the influence of his Norman queen Emma. During the reign of Edward the Confessor (1042–1066), definite strides were taken in spreading Norman ideas to England. Castles were first built in England in his reign under the direction especially of his Norman marcher lord Ralph the Timid. Encastellation began in earnest under William the Conqueror in the years immediately following the Battle of Hastings. Castles of the motte-and-bailey were erected quickly all over the country to subdue the locals and prevent foreign invasions by rival claimants to the throne. Within a matter of years, England was fully castled. Most of these castles belonged to the king or one of his tenants-in-chief. The construction of numerous castles by minor lords was a feature, as in most places, of the reign of weaker kings. After the iron hand of William's sons had passed, Stephen took the throne and the Anarchy (1135–1152) of civil war which characterised his reign saw the proliferation of adulterine (unauthorised) castles: to the number of 1,115, according to one chronicler. Wales The Welsh Marches had been encastellated from an early